Intrapleural pressure during expiration.

Intrapleural pressure is the air pressure in the pleural cavity and also exists between visceral and parietal pleurae. This pressure majorly depends on ventilation phase, the volume of the intrapleural cavity and atmospheric pressure. During expiration, the Intrapleural pressure in the pleural cavity becomes less negative which is commonly known as negative pressure.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.

you know they are heterozygous for a trait because they have it as jj or jj.